<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>0000_画圆</title>
</head>
<body>
  <canvas id="canvas" width="600" height="600"></canvas>
</body>
<script>
  const canvas = document.getElementById('canvas');
  const ctx = canvas.getContext('2d');
  ctx.rotate(45 * Math.PI / 180);
  ctx.fillRect(70,0,100,30);

// reset current transformation matrix to the identity matrix
  ctx.setTransform(1, 0, 0, 1, 0, 0); 

</script>
</html>